In recent years, as superconducting wires, oxide superconducting wires (hereinafter, simply referred to as superconducting wires) have been developed, which are referred to as bismuth-based superconducting wires such as Bi2212 (Bi2Sr2CaCu2O8+δ) or Bi2223 (Bi2Sr2Ca2Cu3O10+δ) or yttrium-based superconducting wires such as RE123 (REBa2Cu3O7-δ), RE: rare earth element, for example, yttrium). Since the superconducting wires can be used in a relatively high temperature region, application development to superconducting coils is advanced. As a superconducting wire, a wire which is formed in a tape shape is known, and a superconducting coil which uses the superconducting wire, a pancake coil, a double pancake coil, or a superconducting coil in which a plurality of these coils are laminated had been developed.
In the superconducting coil, an electrode for supplying current to the wound superconducting wire is provided. Since the electrode is formed of a normal conductive member, a structure for decreasing heat generation from the electrode is required. For example, in a superconducting coil disclosed in Patent Document 1, an end portion of a wound superconducting wire is drawn out and is soldered so as to follow an electrode formed in an L shape. Accordingly, heat generation in the electrode is decreased.